Mushroom Compost

flyfiishn · January 14, 2015

Hello All.

I have run across some compost that is for use on a local mushroom farm and they told me to use as much of it as I would like in return for some walnuts I gave them. To clarify, this is brand new, unused compost. I believe he said in their mixture they use mostly chicken manure, crushed rice hulls, rice straw, potash and some lime and gyp. Not sure on the percentages, and they are probably unlikely to tell me as its proprietary.

My question is, how much should I use in my beds. I am thinking 50-50 mix in with my existing soil to avoid using a compost that may be "too hot." Also, I am wondering when I should begin mixing it in..... now or around plant time in Mid April? I currently have a little vetch seeded into the topsoil that I plan on tilling in around march as well.

any advise is welcome!

thanks all.

shelleybean · January 14, 2015

I've had mushroom compost added the last two years and I've been really happy with it. I have raised beds, 18 inches deep, and we add a 3 inch layer to the top and dig it in. I add it in February and start planting in March. At first, I, too, was concerned about it being too hot and not being able to germinate seeds sown directly, but have not had any problems. I don't know the NPK for this either. The guy that takes care of my lawn and all my pruning and weed control, etc. orders this for me from somebody in Bucks County, Pa. so I have a middleman involved. I don't know exactly where this stuff comes form, just that they have to order it ahead of time. The stuff that was originally used to fill my raised beds, which was from a landscaper, was not holding water. Since I added this compost, that's no longer a problem for me. Sorry I can't help more, but that is my experience with it. I just talked to my guy yesterday and told him I'd be in touch shortly about my compost. I will use it as long as I can get it. I should mention that I also use Tomato Tone, Garden Tone and Age Old Bloom in addition to the compost. No problems with burning the seedlings. Good luck!

Salsacharley · January 14, 2015

It would be good to know how much potash is added. Natural compost should have a pretty good NPK ratio without potash added (IMO).

I've used bagged mushroom compost from one of the big box stores and it worked quite well and I even had mushrooms sprouting up in my garden. They didn't seem to cause any problems.

flyfiishn · January 15, 2015

thanks to all so far. Help is appreciated!

FLRedHeart · January 15, 2015

Shelley and Charlie, really sounds like you are both using spent mushroom compost which is no longer productive for commercially growing mushrooms and has lower residual nutrients, like a commercial rated NPK of around 0.9-0.7-0.5. That because Charlie mentions he gets mushrooms and Shelley because is sort of being sold as a commercial product.

Fresh mushroom compost has an N of around 2.5% which is pretty hot. Flyfish, that's what you say you are getting,. and it is confusing I think because everyone calls the spent stuff "mushroom compost" because it includes a bit of spent mushroom too and it is a byproduct that needs to be commercially sold. I'm posting because I just would watch out about that. I was going to use the spent stuff last year because the spent compost you mentioned for great aerated soil, but I changed my mind since all the spent stuff that was reasonable to get contained more pesticide accumulation from growing the mushroom crops than I was comfortable getting.

About when to work the fresh stuff into the soil, really depends I think and you should just ask them how long they have the compost sitting there or if purchased if it is supposted to weather and for how long top get properly composted for the mushrooms at minimum since mushrooms grow on logs probably could help if it sat in a pile longer. Good luck and sorry not to be more helpful.

flyfiishn · January 21, 2015

Clarification:

Yes indeed, the stuff I am getting is "fresh" as in unused. They are actively turning about 4 acres of piles for their mushroom operation and are allowing me to take some of it that is headed to the mushroom silos for growing new mushrooms. This is not the depleted or leftover product.

shelleybean · January 21, 2015

It's almost time for me to place my call for mine, so I'll ask for clarification. It's done a very good job of holding the moisture in but there are a lot of cheaper products that would achieve that, as well. I'll report back when I get an answer. Thanks.

Tracydr · January 24, 2015

Quote:

Originally Posted by flyfiishn

Hello All.

I have run across some compost that is for use on a local mushroom farm and they told me to use as much of it as I would like in return for some walnuts I gave them. To clarify, this is brand new, unused compost. I believe he said in their mixture they use mostly chicken manure, crushed rice hulls, rice straw, potash and some lime and gyp. Not sure on the percentages, and they are probably unlikely to tell me as its proprietary.

My question is, how much should I use in my beds. I am thinking 50-50 mix in with my existing soil to avoid using a compost that may be "too hot." Also, I am wondering when I should begin mixing it in..... now or around plant time in Mid April? I currently have a little vetch seeded into the topsoil that I plan on tilling in around march as well.

any advise is welcome!
He sure to check the pH. My experience with rice hulls is high pH and nothing would grow with it until they broke down completely.

thanks all.

Redbaron · January 24, 2015

I went to the big box store today to buy Jiffy seed starting mix. They had a couple broken bags laying around of mushroom compost potting soil and cow manure etc.... All 50% off and cheap to start with. There is my seed starting mix for the year! I'll just mix them all up and let you know how it goes!

shelleybean · January 29, 2015

From what I'm reading online, it's all what they call SMC, spent mushroom compost. There are nutrients in it but its very good at helping hold moisture, which is the reason I wanted it. If I get it by the truckload from my lawn guy like I do, it's this or the stuff from the city, and I don't want to stuff from the city.

shelleybean · January 29, 2015

If you want to research further, check out www.mushroomcompost.org for some interesting info, including nutrient analysis and info on pH. Also the salts that are in mushroom compost.

I'm going to stick with the product I've been using, the SMC from Bucks County. I've been happy with the way it's changed my garden and because I have these guys to bring it to me and spread it over the beds and dig it in, it's the easiest and best solution for me. Your mileage may vary, of course.

snugglekitten · January 31, 2015

When I used innoculated soil from spent mushroom compost, it changed the flavor the tomato , perhaps it changed the Ph level, not sure.

Also from what I read - it could contain residual pesticides so be careful.

January 14, 2015	#1
flyfiishn Tomatovillian™ Join Date: May 2014 Location: Northern CA Posts: 80	Mushroom Compost Hello All. I have run across some compost that is for use on a local mushroom farm and they told me to use as much of it as I would like in return for some walnuts I gave them. To clarify, this is brand new, unused compost. I believe he said in their mixture they use mostly chicken manure, crushed rice hulls, rice straw, potash and some lime and gyp. Not sure on the percentages, and they are probably unlikely to tell me as its proprietary. My question is, how much should I use in my beds. I am thinking 50-50 mix in with my existing soil to avoid using a compost that may be "too hot." Also, I am wondering when I should begin mixing it in..... now or around plant time in Mid April? I currently have a little vetch seeded into the topsoil that I plan on tilling in around march as well. any advise is welcome! thanks all.

January 14, 2015	#2
shelleybean Tomatovillian™ Join Date: Feb 2006 Location: Virginia Beach Posts: 2,648	I've had mushroom compost added the last two years and I've been really happy with it. I have raised beds, 18 inches deep, and we add a 3 inch layer to the top and dig it in. I add it in February and start planting in March. At first, I, too, was concerned about it being too hot and not being able to germinate seeds sown directly, but have not had any problems. I don't know the NPK for this either. The guy that takes care of my lawn and all my pruning and weed control, etc. orders this for me from somebody in Bucks County, Pa. so I have a middleman involved. I don't know exactly where this stuff comes form, just that they have to order it ahead of time. The stuff that was originally used to fill my raised beds, which was from a landscaper, was not holding water. Since I added this compost, that's no longer a problem for me. Sorry I can't help more, but that is my experience with it. I just talked to my guy yesterday and told him I'd be in touch shortly about my compost. I will use it as long as I can get it. I should mention that I also use Tomato Tone, Garden Tone and Age Old Bloom in addition to the compost. No problems with burning the seedlings. Good luck! __________________ Michele

January 21, 2015	#7
shelleybean Tomatovillian™ Join Date: Feb 2006 Location: Virginia Beach Posts: 2,648	It's almost time for me to place my call for mine, so I'll ask for clarification. It's done a very good job of holding the moisture in but there are a lot of cheaper products that would achieve that, as well. I'll report back when I get an answer. Thanks. __________________ Michele

January 24, 2015	#9
Redbaron Tomatovillian™ Join Date: Sep 2012 Location: Oklahoma Posts: 4,488	I went to the big box store today to buy Jiffy seed starting mix. They had a couple broken bags laying around of mushroom compost potting soil and cow manure etc.... All 50% off and cheap to start with. There is my seed starting mix for the year! I'll just mix them all up and let you know how it goes! __________________ Scott AKA The Redbaron "Permaculture is a philosophy of working with, rather than against nature; of protracted & thoughtful observation rather than protracted & thoughtless labour; & of looking at plants & animals in all their functions, rather than treating any area as a single-product system." Bill Mollison co-founder of permaculture

January 29, 2015	#10
shelleybean Tomatovillian™ Join Date: Feb 2006 Location: Virginia Beach Posts: 2,648	From what I'm reading online, it's all what they call SMC, spent mushroom compost. There are nutrients in it but its very good at helping hold moisture, which is the reason I wanted it. If I get it by the truckload from my lawn guy like I do, it's this or the stuff from the city, and I don't want to stuff from the city. __________________ Michele

January 14, 2015	#3
Salsacharley Tomatovillian™ Join Date: May 2013 Location: New Mexico Posts: 2,052	It would be good to know how much potash is added. Natural compost should have a pretty good NPK ratio without potash added (IMO). I've used bagged mushroom compost from one of the big box stores and it worked quite well and I even had mushrooms sprouting up in my garden. They didn't seem to cause any problems.

January 15, 2015	#4
flyfiishn Tomatovillian™ Join Date: May 2014 Location: Northern CA Posts: 80	thanks to all so far. Help is appreciated!

January 15, 2015	#5
FLRedHeart Tomatovillian™ Join Date: Aug 2014 Location: FL 8b/9a Posts: 262	Shelley and Charlie, really sounds like you are both using spent mushroom compost which is no longer productive for commercially growing mushrooms and has lower residual nutrients, like a commercial rated NPK of around 0.9-0.7-0.5. That because Charlie mentions he gets mushrooms and Shelley because is sort of being sold as a commercial product. Fresh mushroom compost has an N of around 2.5% which is pretty hot. Flyfish, that's what you say you are getting,. and it is confusing I think because everyone calls the spent stuff "mushroom compost" because it includes a bit of spent mushroom too and it is a byproduct that needs to be commercially sold. I'm posting because I just would watch out about that. I was going to use the spent stuff last year because the spent compost you mentioned for great aerated soil, but I changed my mind since all the spent stuff that was reasonable to get contained more pesticide accumulation from growing the mushroom crops than I was comfortable getting. About when to work the fresh stuff into the soil, really depends I think and you should just ask them how long they have the compost sitting there or if purchased if it is supposted to weather and for how long top get properly composted for the mushrooms at minimum since mushrooms grow on logs probably could help if it sat in a pile longer. Good luck and sorry not to be more helpful.

January 31, 2015	#12
snugglekitten BANNED Join Date: Jan 2012 Location: Land of the White Eagle Posts: 341	When I used innoculated soil from spent mushroom compost, it changed the flavor the tomato , perhaps it changed the Ph level, not sure. Also from what I read - it could contain residual pesticides so be careful. Last edited by snugglekitten; January 31, 2015 at 09:39 AM.